Kate Winslet found filming 'The Mountain Between Us' "really f***ing scary".
The Oscar-winning actress stars with Idris Elba in the thriller as survivors of a plane crash left stranded on a remote, snowy mountain, and though she enjoyed the challenge of being largely isolated while shooting in temperatures of -38 deg C in the Canadian Rockies, it was the toughest thing she'd ever done.
She said: "Normally on a film, there's a group of people who keep their eyes on the actors and make sure they have everything they need, but this was very much a case of every man for themselves, which was good.
"I'm like that anyway. If I'm going up a mountain, I want to make sure I've got a head torch and enough hot packs and food for the day, so I'd pack my rucksack of goodies to make sure I had what I needed - and a few extra teabags to boot - if bad weather set in and we were stuck up there.
"That sad, it was really f***ing scary. It was very remote up there."
However, the 41-year-old actress - who took her own daily supply of essentials, including M&Ms, coffee sachets, flasks of chicken broth and battery-heated gloves, to set every day - was thankful to have safety experts on hand to guide her and her co-star.
She told Glamour magazine: "We had an amazing group of mountain-safety people who'd been scouting the area for six months at high altitude. They knew exactly what was going on underneath the drifts of snow, where to walk and where not to walk."
One of the toughest scenes in the film was when Kate's character plunged through ice on a lake and had to be rescued by Idris, and though the actress opted to shoot the scene without a stunt double, she was more worried about her hair than falling ill from the freezing conditions.
She admitted: "The most difficult part was being dragged soaking wet through the cold snow, but my biggest fear was not actually getting pneumonia, it was Idris treading on my hair. I didn't want to ruin a take by going, 'Argh, he's stepping on my hair!'
"And however hard it looks for me, it was harder for Idris to anchor his feet on the ice; it was freezing cold, he was also soaking wet, and I weigh a ton because all those clothes I'm wearing are soaked through."